Magnetic sheet feeder



Aug- 15, 1961 D. BucclcoNE MAGNETIC SHEET FEEDER 6 Sheets-Sheet l FiledFeb. 5. 1959 u Nt Aug. 15, 1961 D. BucclcoNE 2,996,297

MAGNETIC SHEET' FEEDER Filed Feb. 5, 1959 6 Sheets-Sheet 2 L lf rllrrnisAug. 15, 1961' D; BucclcoNE MAGNETIC SHEET FEEDER Filed Feb. 5, 1959 6Sheets-Sheet I5v si Ll;

Aug. 15, 1961 D. BucclcoNE MAGNETIC SHEET FEEDER 6 Sheets-Sheet 4 FiledFeb. 5, 1959 INVENTOR. pa rl'o Buccz'corze BY v MM# ma l Aug. 15, 1961D. BucclcoNE 2,996,297

4 MAGNETIC SHEET FEEDER Filed Feb. 5, 3.959 6 Sheets-Sheet 6 Unite Statsarent O 2,996,297 MAGNETIC SHEET FEEDER Dario Buccicone, Gary, Ind.,assigner to 'Bucciconi Eugineerng Co., Inc., Gary, Ind., a corporationof Indiana Filed Feb. 5, 1959, Ser. No. 791,'450 21 Claims.(Cl.\271-`16) liability of damage as the sheets are removed from thepile.

It is a more specific object of the invention to provide apparatus forthe automatic feeding of metal sheets from the top of a pile thereofwherein each successive sheet is lifted along its entire length by amagnetic conveyor and advanced away from the pile without the use ofpinch rolls and without metallic contact.

It is a still more specific object of the invention to provide anapparatus for removing successive metal sheets from the top of a pilethereof and for advancing the same therefrom in a rapid and eicientmanner, wherein the sheets are lifted bodily from the top of the pile byan overhead magnetic conveyor which may be operated at a relatively highrate of speed and which will pick up each sheet and advance the samewithout disturbing the next succeeding sheet so that there is no contactbetween the successive sheets during removal from the pile norsubsequently and damage to the sheets It is another object of theinvention to provide an apparatus for automatically feeding metal sheetsfrom a pile wherein a magnetic conveyor is arranged above the pile andoperated to lift each successive sheet, which conveyor raises the sheetvertically throughout its entire length and breadth, and thereafterconveys each sheet forwardly lwhile holding the same free of anymetallic Contact, until the sheet is moved clear of the pile.

It is a further object of the invention to provide an apparatus forfeeding metal sheets om a pile thereof |which comprises an uprightsupporting frame structure having a bed disposed therein on which a pileof sheets is supported and an overhead magnetic conveyor which isoperated to remove successive sheets from the top of the pile and conveythe 'same therefrom in a direction laterally of the pile, together withmechanism for raising and lowering the sheet supporting bed andmechanism for automatically controlling the same to maintain the top ofthe pile of sheets at a predetermined distance below the conveyor.

It is a still further object of the invention to provide an apparatusfor feeding metal sheets from a pile which comprises a supporting framehaving an overhead magnetic conveyor which is adapted to lift successivesheets from the top of a pile positioned on a bed disposed beneath theconveyor and to convey the sheets one by one in a direction laterally ofthe pile', a raising and lowering mechanism associated lwith the bed andcontrol mechanism for determining the elevation of the top sheet in thepile and for automatically raising the bed as successive sheets areremoved from the pile thereon.

Another object of the invention is to provide an ap- 7 paratus forunpiling metal sheets lwhich comprises a bed stmcture for supportingthereon a pile of the sheets, an

miice overhead magnetic conveyor which is operable to lift the sheetssuccessively from the top of the pile and to forward the same away fromthe pile, mechanism for raising and lowering the bed structure, and anadjustable control mechanism for initially determining the elevation ofthe top sheet in the pile and for raising the bed structure assuccessive sheets are removed from the pile so that the topmost sheet ispositioned a predetermined distance below the conveyor and successivesingle sheets are removed from the pile.

Still another object of the invention is to provide in a sheet feedingapparatus of the type which employs an overhead magnetic conveyor forremoving the sheets from the top of a pile, a mechanism for separatingthe topmost sheets in the pile along the full length of the leading edgethereof, `which mechanism spreads the edges of the sheets in an upwarddirection toward the conveyor and facilitates the feeding of a singlesheet at a time.

A further object of the invention is to provide in a sheet feedingapparatus having an overhead magnetic feeding conveyor a mechanism whichis operative adjacent the leading edge of the sheets at the top of thepile for initially engaging and lifting the topmost sheet in thevertical direction toward the magnetic conveyor and for controlling theelevation of the pile so that the top sheet will be spaced from theconveyor a sucient distance for it to be picked up by the conveyorwithout picking up the next sheet in the pile.

Another object of the invention is to provide in a metal sheet feedingapparatus which is characterized by an overhead magnetic feedingconveyor, a mechanism for gripping the top sheet which is being fed froma pile adjacent the leading edge thereof and for lifting the same towardthe magnetic conveyor so as to insure that the sheet will be heldagainst the bottom of the conveyor in proper position for feeding.

Another object of the invention is to provide in a metal sheet feedingapparatus of the type which employs an overhead magnetic feedingconveyor a height gauging mechanism for determining Ithe elevation ofthe top surface of the top sheet in the pile rela-tive to the bottomsurface of the conveyor which gauge mechanism includes gripper fingersfor engaging the top sheet near its leading edge and for lifting thesame toward the conveyor so as -to insure that the leading edge of thesheet is lifted clear of the pile and into the effective zone ofmagnetic attraction for holding the same against the bottom surface ofthe conveyor.

Another and still more specific object of the invention is to provide anapparatus for unpiling metal sheets which comprises an uprightsupporting frame, a bed structure for supporting thereon a pile of thesheets, an over-head magnetic conveyor which is operable to lift thesheets successfully from the top of the pile and to forward the sameaway from the pile, mechanism `for raising and lowering the bedsrtucture, mechanism for energizing and deenergizing the magnets in themagnetic conveyor, and control mechanism for automatically determiningthe vertical position orf the bed and for operating the conveyor magnetsin proper timed relation whereby each successive sheet is picked upbodily and fed from the pile without disturbing the neXt succeedingsheet in the top of the pile. l

Another object of the invention is to provide a sheet handling apparatusof the character described wherein the bed for supporting the pile ofsheets comprises a plurality of rollers onto which the pile is initiallymoved and a brake mechanism cooperating with the rollers to retard themovement of the pile as it traverses the bed.

A further object of the invention is to provide a sheet handlingapparatus of the type described wherein the operation of the magnets inthe sheet forwarding con- Y veyor is electrically controlled by inductoswitches or similar control elements which are actuated by passage ofthe sheets without any contact of the sheets with the control elements.Y

These and other objects and advantages of the invention will be apparentfrom a consideration of the sheet handling apparauts which is shown byway of illustration in the accompanying drawings, wherein:

FIGURE l is a plan view, with portions broken away, of a sheet handlingapparatus having embodied therein the principal features of theinvention;

FIGURE 2 is a side elevation of the apparatus, with portions brokenVaway;

FIGURE 3 is an elevation of the loading end of the machine, withportions broken away;

FIGURE 4 is an elevation of the discharge end of the machine, withportions broken away;

FIGURE 5 is a cross section, to an enl-arged scale, taken on the line5-5 of FIGURE 1, with portions broken away;

FIGURE 6 is a fragmentary cross section, to an enlarged scale, taken onthe line 6 6 of FIGURE l;

FIGURE 7 is a cross section taken on the line 7-7 of FIGURE 6 on alarger scale;

FIGURE 8 is a fragmentary cross section, taken on the line 8-8 of FIGURE46;

FIGURE 9 is a fragmentary cross section, taken on the line 9-9 of FIGURE7;

FIGURE l() is a partial cross section taken on line 10-119 of FIGURE `6,to a larger scale and with portions broken away;

FIGURE 1l is a fragmentary section taken on the line 11-11 of FIGURE 10,to a larger scale;

FIGURE l2 is a fragmentary section taken on the line 12--12 of FIGUREl0, to a larger scale;

FIGURE 13 is a fragmentary section taken on the line 13-13 of FIGURE l0,to a larger scale; and

FIGURES 14 and l5 are diagrammatic layouts of the electrical controlsfor the apparatus.

The apparatus which is illustrated in the `drawings and which hasincorporated therein the principles of the invention is designed toremove individual metal sheets 1li from a stack or pile 11 of the sameand to forward the same away-from the pile. It is particularly adaptedfor use in unpiling the sheets by lifting successive top sheets from thepile in 'a vertical direction and thereafter feeding them one by one ina lateral direction to processing apparatus for further operations onthe sheets.

The apparatus comprises an uprightV supporting frame structure 12(FIGURES 1 to 4) on which there is mounted a horizontally disposedvertically reciprocable bed structure 13 lfor receiving a stack or pileof metal sheets 10 and an overhead magnetic conveyor 14, the latterbeing operable to lift successive sheets 1l) from the pile 11 and todeliver the same in single le relation at one end of the apparatus.

The supporting frame structure r12 comprises longi- Itudinally spacedend frames 15 and 16 which are connected at the bottom by parallel,laterally spaced, longitudinally extending side beams 17 and at the topby similar longitudinally extending side beams 18. The end framestructure 15 at the entry or receiving end of the apparatus comprises a-horizontal base plate 19 (FIG- URE 3), laterally spaced vertical sideframe plates 20 Y and a connecting horizontal top plate 221. Arelatively Vshort fixed platform 22 over which a pile of sheets is movedinto the apparatus is arranged over the base plate 19 and comprises aplurality of rollers 23 and a supporting frame structure 24, the latterbeing secured between the side plates 20. At the inner edges of the sideplates i vertically extending screw receiving housings 25 are lprovidedwhich are channel shaped in horizontal cross Y section and which arearranged with their open sides facing inwardly toward each other.

The end frame structure 15 at the other end of the apparatus comprises ahorizontal bottom plate 26, a pair of laterally spaced side plates 27anda transversely and vertically extending inner cross plate 28 whichconnects ther inner edges of t-he vertical side'plates 27. Horizontallyextending top plates 30 are supported on the upper edges of the sideframe plates 27 by angle brackets 31. Vertically extending screwreceiving housings 32 are provided at the inner edges of the verticalside plates which are channel shaped in horizontal cross section andwhich are arranged with their open sides facing inwardly towards eachother in the same manner -as the screw housings25 in the end frame 15 atthe other end of the apparatus.

The vertically movable bed structure 13 on which the pile 11 of sheets10 is supported during the feeding or unpiling operation comprises ahorizontally disposed frame 33 and a plurality of rollers 34 supportedthereon. The frame 33 is of generally rectangular shape and comprisesoppositely disposed parallel longitudinally extending side frame members35 and an intermediate longitudinal supporting member 36 which isparallel to the side members 35 and which divides the frame into twolongitudinally extending rectangular sections. The side frame members orrails 35 and the intermediate rail 36 are joined at the ends by crossbrace members or plates 37 With appropriate intermediate cross bracemembers as required. The rollers 34 extend in transversely aligned andpaired relation on the frame 33t, being rotatably supported in suitablebearing formations 39 which are mounted on the side rails 35 and theintermediate center rail 36 and which have upwardly opening slots forVreceiving the ends of the roller carrying shafts 38.

The frame 33 is supported at its opposite ends by means of saddlemembers 40 (FIGURES 5, 6 and 8) extending transversely of the machine.Each of the saddle members 40 comprises an upwardly and inwardly facingangle member 41 having a cross bar 42 supported on its horizontallydisposed bottom ange 43. The side rails 35 and the center rail 36 of theframe 33 are provided at opposite ends of the frame with longitudinallyprojecting, vertically extending bearing plates 44 each having on itsbottom edge a downwardly opening recess or slot 45 (FIGURE 6) forengaging therein the cross bar 42 of the saddle 40. Each of the saddles40 is provided at each end of the angle member 41 with a verticallyextending end plate 46 (FIGURES 5 and 8) which has mounted on its outerface a pair of spaced, outwardly extending, vertical plates 47 whichform a downwardly opening nut socket for engaging over a nut 48. The nut48 is in the form of a truncated pyramid with upwardly facing curvedbearing surfaces 49 on opposite faces thereof on which the lower edgesof the vertical plates 47 are seated, the edges Y of the plates 47having a curvature corresponding to that manner in its respectivehousing, being supported at its lower end by a bearing member 52 (FIGURE5) and at its upper end by a bearing member 53. The screw 51 has avertical extension member 54 at its upper end which is supported inbearing members 55 and 56 in a vertically disposed housing extension 57which is mounted on the top of the end frame structure and forms acontinuation of the housing 32, the housing 25 on the end frame 15having a corresponding vertical extension 58.

The extension memberV S4 on each lifting screw 51 is provided on itsupper end with a worm gear 59 and each of the Worm gears 59 is fintoothed engagement with a worm 60 on one of the two parallel operatingor drive shafts 61 which extend longitudinally at opposite sides of thelapparatus.

The drive shafts 61 are supported in sui-table bearings at theiropposite ends in the housing extensions 57 and 58 and intermediate thelatter in longitudinally spaced bearing supports or brackets '62 whichare mounted on the upper surfaces of the top side rails 18. Each of theshafts 61 is connected at the pile receiving end of the apparatus by asuitable coupling 63 to a gear reduction unit 64, a pair of the latterbeing mounted in laterally spaced relation on the top plate 21 of theend frame 15. The gear reduction units 64 are driven by a transverselyextending connecting drive shaft 65 which carries a drive pulley 66connected by a drive belt 67 with the pulley 68 on a drive motor 70 alsomounted on the top frame plate 21. The drive shaft 65 is connected tothe drive pulley 66 through an air operated clutch unit 71 and a brakeunit 72, also air operated, is provided for quick stopping of the shaft65, ythe brake unit 712 being mounted on an upstanding support bracket72 on the frame plate 21.

The frame 33 of the bed member 13 is positioned somewhat higher at theentrance or pile receiving end than at the opposite end thereof so thatwhen a pile of sheets 11 is rolled thereon it will move by gravitytowards the opposite or sheet discharging end and a Iroller brakingmechanism (FIGURES to 9) is provided on the bed 13 to control thisgravitational movement of the pile of sheets 11. The braking arrangementcomprises four rectangular frames 73 (FIGURES 6 to 8) which arepositioned in horizontally disposed relation within the frame 33adjacent the `discharge end of the apparatus. Each brake frame 73 isvertically movable in a `guideway formed by longitudinally spaced,vertically extending angle brackets 74 which are arranged on the sideand center rails 35 and 36, respectively, of the frame 33 and whichcooperate therewith to form vertical guideways in which the four cornersof each frame 73 are received. Each of the brake frames 73 comprisesthree transversely extending longitudinally spaced U frames 75 (FIGURES6 to 9) arranged with leg portions projecting upwardly betweensuccessive pairs of rollers 34, two of these U frames constituting theend members of the frame 73. The U frames 75 carry a cross bar 76 on theupper ends of their legs on which roller engaging braking plates orshoes 77 are mounted which have beveled side edges positioned tofrictionally engage with the surfaces of the rollers 34 when the frame73 is lowered by the mechanism which will be described. The brake shoecarrying U frames 75 are connected at their ends by longitudinallyextending, laterally spaced channel shaped frame members 78 which arearranged rwith their open sides facing towards the outside edge of theapparatus and which constitute the side members of the frame 73. Theside frame members 78 are apertured at 79 (FIGURES 7 and 9) toaccommodate transversely extending operating shafts 80, each of which ismounted in suitable bearing sleeves 81 and SR2 in the bearing formingmembers 83 and 84, the latter being mounted in the side and center rails35 and 36, respectively- 'I'he operating shafts 80 extend the full-width of the bed structure 13 and carry cam members 85 for engagingwith each of the brake side frame members 78. The cam members 85 arekeyed on each shaft 80 so that the track forming eccentric periphery 86of each cam 85 is positioned between the vertically spaced upper andlower flanges 87 and 88 of the side frame members 7 8 whereby when theshafts 80 are rotated the brake frames 73 are raised and lowered. Theshafts 80 each carry in tixed relation thereon two axially spacedoperating arms 89 which have their free ends pivotally connected at 90to longitudinally extending links 91, the latter being spacedtransversely of the bed structure 13. One end of each link 91 is pivotedat 92 to the end of the piston 93 of an hydraulic cylinder or motor 94,the

spaced brackets 96 mounted on the cross frame member 37 at the dischargeend of the bed 13. Each of the hydraulic motors 94 and its linkage forconnecting the same to the shafts 80 is located intermediate the sideframe members 78 of each of the end brake frames 73 and each motor 94 isconnected to all four shafts 80, the motors being operated insynchronism to apply or release the brake shoes 77 as required.

'I'he magnetic conveyor assembly 14 (FIGURES 1, 2, 5 and 6) comprises aplurality of laterally spaced elongate magnetic rail units y100 whichare mounted to extend lengthwise of the apparatus above the bed or table|13 and which are supported on longitudinally spaced cross beams 101 and102. Each of the magnetic rail units 100 comprises a pair of travelingbelts 103 mounted on end pulleys 104 and 105 secured on cross shafts 104and 105', respectively. A series of electromagnets indicated at 106 arecarried on the units 100 in longitudinally spaced relation along thelower run of the conveyor belts 103. These magnetic rail units 100 arepreferably constructed in accordance with the disclosure in Patent No.2,642,174, dated lune 16, 1953, to which reference is made for detailsnot herein disclosed. The magnetic conveyor units 100 are driven byrotation of the end shaft 104 which is mounted at the opposite endsthereof in bearing formations 107 (FIGURE 4) projecting upwardly of theend frame plates 30 and has one end extended beyond the frame side plate27 to receive a drive pulley 108 which is connected by a drive belt 109with a power pulley 110 on a drive motor and gear reduction unit 111supported on the base plate 26 of the end frame 16. The shaft 105 andvthe pulleys 1015 at the other end of the apparatus are idler memberssupporting the conveyor belts at that end of the units 100, the shaft105 being suitably supported at its ends.

A delivery platform 1112 (FIGURES l, 2, 4 and 6) is arranged at thedischarge end of the apparatus below the discharge end of the magneticconveyor assembly 14 which comprises a plurality of longitudinallyspaced transversely extending sectional rollers 113 supported on a framestructure 114 mounted between the side plates 27 of the end frame 16immediately below the end of the conveyor 14 so as to receive andsupport thereon each successive sheet 10 as -it is advanced over therollers 113 by the operation of the conveyor 14. The rollers 113 aremounted on shafts 115 and one of the shafts ,115 carries a sprocket 1-16which is connected by means of a drive chain 117 with a sprocket 118 onthe cross shaft 104', the chain 117 being =looped around idler sprockets120 suitably supported below the roll shafts L15, At the other end theshafts 115 carry sprockets 121 which are connected in paired relation bydrive chains I122 with the driven shaft 115 which carries the drivesprocket 116.

A sheet spreader 125 (FIGURES 6, 10 and l2) is provided at the top ofthe vertical plate 28 to spread the edges of the topmost sheets on thepile in an upward direction at the start of the lifting cycle. Thespreader 125 comprises an angular housing or cover member P1126 whichhas a vertical leg or flange 127 secured to the vertical plate 28 withthe surfaces of the flange and plate ush and a top leg or flange 128extending horizontally in alignment with the delivery table members 122.The cover or housing member 126 is formed of stainless steel or othernon-magnetic material and extends along the entire width of the machine.The vertical ange 127 of the housing 126 is provided at the top thereofwith a series of transversely spaced rectangular apertures 130 and thehorizontal flange 128 supports in depending relation thereon a pluralityof magnetic spreader units 131 which are transversely spaced and alignedwith certain of the apertures 130. Each of the spreader units 131comprises two electromagnetic coils 132 on a pole member t133 which issecured at its upper end to a cross plate 134, the latter beingsuspended from latter being pivotally mounted at 95 in a pair 0f.laterally 75 the top Harige. 127 of cover '126 by bolts and spacers 135of non-magnetic material. 'Ihe cross plate 134 has a forwardly extendingupwardly slanted front edge portion 136 land forms an extension ofthepole pieces 133 as well as a support for the units 131. The pole pieces133 are connected at the bottom of the units by a cross member 137 ofangular sectionwhich has a horizontal leg or llange 138 positionedbeneath the units 131 and a vertical leg or flange I139 extendingbetween Vthe coils 132 of the unitsv 131 and the vertical flange portion127 of the cover member 126. A bar 140 is secured in an upwardly andforwardly angled position on the upper'edge of theflange 139 and aseries of rectangular members 141 are secured in vertically extendingrelation on the upper edge thereof, one for each of the units 131. Themembers 141r and the poles 133 are aligned with the apertures 130 sothat the members 1411 extend into the apertures 130, as illustrated inFIGURE 12, and the members 141 are vertically spaced from the top poleextension 136 so that when the coils 132 of the units 131 are energized,the path of the ilux extends across thegap provided between the poleextensions 141 and 136 with the result that when the top of the pile ofsheets is brought to a point between the members 141 and 1136, the edgesof the topmost sheets 'will be spread apart as illustrated in FIGURE 12,the separating occurring along the entire edge of the topmost sheet. Thecoils 132 (FIGURE Y15) of the separator units 131 are energized withrtheclosing of switch S1 (FIGURES l5) and the application of power to themagnet coils in the conveyor 14 so that separation of .the leading edgeof the top sheet from Athe next sheet in the pile -at the beginning ofthe lifting cycle is insured. l

A top-of-the-pile limit switch 142 (FIGURE 11) is mounted on thevertical end plate 28 below the separator device 125 and is providedYwith an operating lever 1143 which is actuated by upward movement ofthe pile of sheets. The operating lever 143 is arranged in verticallyextending relation on a mounting bracket 4144, the latter Vbeingsupported in depending relation on the bottom face of the horizontal leg128 of the separator cover member 126 and carrying at its lower end abifurcated portion 146 having a pivot pin 148 on which the lever 143 issupported intermediate its top and bottom ends.

A The upper end of the lever 143 has a cam formingV portion 150 (FIGURESl() and lll) which-extends through one of the slots 130 in the verticaliange 127 of the separator 4cover 126. The lower end 151 of the switchof the pile, to stop the upward movement of the bed 13. An apparatus isprovided at the discharge end of the machine for controlling Vthe heightof the top sheet in the pile or the distance between the top sheet andthe bottom face of the conveyor 14. This apparatus 154 (FIGURES l, 10,and 13) also serves to lift the leading edge of the top sheet toward theconveyor so as to insure Y that the leading edge of the sheet isproperly positioned against the conveyor belts as the sheet begins itsforward movement'on the Vconveyor 14. This apparatus insures that thesheets will be consistently picked up and sent forward even though thecondition of the sheets varies.

The height control and sheet edge lifting apparatus 154 is supported ona channel 155 which is mounted on and extends across the top of theconveyor rail units 100. The apparatus comprises two solenoid units 156and `157 which are identical in construction and operation, with one ofthe units 156 being arranged to actuate a switch -160 which controls thevertical movement of the pile supporting bed 13, as hereinafterdescribed. Both solenoid units l156 and 157 are supported on the channel155 in dependingY relation between the conveyor units Both of theseunits include vertically movable plungers which are adapted to rstsimultaneously engage the top surface ofthe top sheetV as the pile islifted by the upwardly moving bed 13 Vand which are then operated tomagnetically grip and raise further the front edge of the topmost sheetof the pile when the bed 13 is stopped by operation of the switch 16with the topmost sheet in the pile at a predetermined distance from thebottom of the conveyor'14 for which the apparatus is adjusted.

The solenoid unit 156 (FIGURE 13) comprises a plurality ofelectromagnetic coils 161, preferably three in number, which arearranged in vertically disposed relation on a brass tube 162 andvenclosed in a tubular housing 163. The housing 163 has a top plate 164and the coils 161 are secured in the housing by a bottom ring 165fastened to the same by bolts or other suitable fastening elements. Thebrass tube 162 is secured at its upper end to a tubular guide section166 which depends from the top plate 164 and has a bore 167 foraccommodating the stem forming upper extension 168 of a verticallymovable solenoid core or plunger member 170 which acts as a sheetlifting finger. The plunger member 170 is raised and lowered byenergizing and de-energizing the coils 161 with the upper limit of itsmovement determined by the depth of the tubular guide 166, the bottomedge of which forms an abutment or limit stop for the top end of theplunger member 170. The member 170 carries-a plate 171 on its lower endwhich is secured by a bolt I172 extending through a washer 172'. Arubber bumperV ring 173 is secured on the bottom face of the plate 171which has its lowerrnost surface in a plane spaced somewhat below thebottom face of the washer `and bolt head so as to-avoid damage to thesheet when the latter is raised intoV contact with the member 170. Thehousing '163 is suspended from the supporting channel by a pair of tubesections 174 which are secured in upstanding relation on the top plate'164 and which are connected in threaded relation to the lower ends of afurther pair of tube sections 175, with the latter extending throughsuitable apertures in the web of the channel 155 and secured thereto bylock nuts 176 so that the vertical position of the housing may beadjusted. The stem 168 Vof the plunger or finger 170 extends through thebore of the guideY member 166 and also through an aperture 177 in thechannel 155.

'Ihe stem 16S of the plunger 170 of the solenoid unit 156 is providedwith a device for operating the switch Vin response to predeterminedupward and downward movement of the plunger 170. To this end the stemmember 168 has an upper end portion 178 of reduced section whichprovides an external shoulder 180 for cooperation with an internalshoulder 181 formed in a sleeve 182 which is slidably supported on theupper end of the stem member 168, and which has an upper end portionwithY a bore of reduced diameter at 183. The sleeve 182 is ofsubstantial length and -is carried on the stem member 168 so that it isVraised by upward move- Vment of the plunger V which exceeds thedistance necessary to bring theV shoulders and 181 into engagement. Arubber washer 184 Vis provided on the plate 164 which limits thedownward movement of the sleeve 182 whenY the plunger 170 is allowed todrop below a predetermined point upon ile-energizing the coils 161. Thesleeve 178 has a section `185 at its upper end which is of smallerexternal diameter and which is adapted to receive the end of theoperating lever 186 of the microswitch '160. Y

The control switch `160 (FIGURE 10) is fixed on a vertically movablecarriage forming member 188 which is mounted in vertically slidablerelation on a post 190 upstanding from a bracket plate 191 secured onthe channel 155. The bracket plate 191 carries an upstanding post-likemember 192 which has secured thereon a generally triangular shaped Yorsegmental dial member between a pair of bracket ears 198 on the slidablecarriage 188. The operating lever 194 is provided with a handle 199 atits outer end which rides on the curved outer edge 200 of the dial 193and Iwhich may carry a latch mechanism (not shown) of a suitable kindfor holding the lever 194 in any desired position. The lever 194 isprovided with a pointer 201 for cooperation with a calibrated plate 202on the dial supporting plate 193, so that the vertical position of theswitch 161? may be adjusted by manually swinging the lever 194.

The switch 160 is operated, upon the arm 186 being tripped by the upwardmovement of the sleeve 182, to stop the upward movement of the pilesupporting bed 13. The sheet lifting plunger 170 rests on the top sheetand is lifted by the latter as the bed 13 moves upwardly to a pointwhich positions the sheet at the proper distance below the conveyor 14for lifting by the magnets in the conveyor rail units 100, this distancebeing previously determined for the weight and thickness of the sheetand the vertical position of the switch 160 being adjusted by settingthe lever 194 at the correct point. As the switch 160 is operated tostop the upward movement of the bed 13 the coils 161 are energized whichresults in further upward movement of the members 170 and also in thesheet being pulled by magnetic force against the bottom end of themembers 170. The members 170 carry the edge of the sheet upwardly intoengagement with the bottom of the conveyor and then continue a shortdistance so that the bottom end is pulled free of the sheet, the latterbeing in eiect stripped from the fingers 170` when it strikes theconveyor. When the sheet is lifted into contact with the bottom of theconveyor units 100 by the pull of the conveyor magnets which areenergized at the same time as the coils 161 and the sheet begins to movelaterally above the top of the pile by operation of the conveyor beltsthe coils 161 are deenergized and the plunger 170 is free to drop downand engage the neXt sheet as the top sheet moves out from under thebottom end of the plunger and the sleeve 182 drops with it. The switch160 is operated, upon the arm 186 being tripped by downward movement ofthe sleeve 182, to restart the upward travel of the pile supporting bed13.

Vertical movement of the pile supporting bed structure 13 and operationof the sheet pickup conveyor 14 are controlled automatically uponloading of a pile of sheets onto the bed 13 and adjusting the heightcontrol mechanism 154 for the thickness and weight of the sheets. Thecircuits for supplying current to the drive motor units 70 and 111 areshown in FIGURES 14 and 15 with the necessary switches, relays and otherelectrical control elements being indicated schematically, the A C.control circuits being shown in FIGURE 14 and the D.C. control circuitfor supplying direct current to the magnet coils in the conveyorassembly 14 being shown in FIG- URE 15.

Referring rst to FIGURE 15, the magnet coils in the conveyor assemblyare divided into groups or sections lengthwise of the apparatus and areconnected with a D.C. current supply line through switch S1 asillustrated, the magnet coils for each section, numbered 1 to 7 inFIGURE 15, being indicated as connected to the contacts K1 to K7 of amain contactor or control relay which is indicated at MC. In FIGURE 14,A.C. current is supplied through switches S2 and S3 to the controlcircuits. The contactor coils for the main contactor MC which controlsthe current for energizing each section or group of magnets areindicated at KL1 to KL7 in FIGURE 14 and the main magnet contactor coilis indicated at MCL in one of three circuits which are controlled by aselector switch indicated at 230. This circuit includes a series ofinducto switches which are spaced along the conveyor assembly 14 andwhich are indicated at C1 to C7. These switches are actuated by passageof the trailing end of each sheet 11 as it is advanced by the conveyor14, with each switch being connected to and controlling the energizingand de-energizing of a group of the magnet coils. While the sheet isbeneath each switch C1 to C7, the switch is closed and the magnet coilscontrolled by the same are energized to hold the sheet against thetraveling conveyor belts. When the trailing end of the sheet has passedbeneath the switch it automatically opens to de-energize the magnetcoils. The main motor unit 111 is controlled by the manually operatedswitch indicated at 231 (FIGURE 14) with forward and reverse operationand normally drives the conveyor belts continuously when the switchV 231is closed for operation of the apparatus. 'I'he motor unit 70 whichdrives the lift screws 51 is operated continuously in accordance withthe position or setting of the selector switch 230 through a liftcontrol 232 which is in a second circuit through the selector switch 230and which controls the speed of the up or down movement of the bed 13with the direction being according to the setting of the selector switch230. The drive shaft 65 is connected and disconnected with the motor 70through the clutch 71 and a quick stopping brake 72 is `associated withthe drive shaft 65, both the clutch 71 and the brake 72 being airoperated under the control of valves which are in turn operated bysolenoids indicated at VC and VB (FIG- URE 14), respectively, in thelift control circuit. An upper limit safety or crash switch 233 (FIGURES5 and 14) for a lift bed 13 is provided, preferably, adjacent the top ofa lift screw 51 for operation by engagement of its operating arm withthe nut 48 to insure that the bed 13 does not rise beyond apredetermined elevation. A similar lower limit switch 234 is provided atthe base of the lift screw 51 to stop the downward movement of the bedat a predetermined fixed point. The switches 233 and 234 are connectedinto the lift control circuit in FIGURE 14 along with the relays XA andZB, the relay XA having a normally open contact XAa in the elevatingcircuit for the lift motor. A top of the bed limit switch 235 isadjustably mounted on the apparatus adjacent the bed so that itsoperating arm will be engaged by a moving part of the bed 13 when thebed reaches a predetermined height so as to initiate the return of thebed to the lowered position for a new pile of sheets. This switch hastwo contacts indicated at 235a and 235b in the lift circuit and themagnet control circuit which are normally closed and which are opened bythe lift bed when the bed reaches the height at which the last sheet isremoved. An inducto switch 236 (FIGURES 1 and 2) is positioned at theleading end of the conveyor 14 which serves as the main control forautomatic operation of the apparatus. The main control switch 236 hastwo contacts 23611 and 236b which are normally closed and open,respectively, and which are in the magnet control circuit along with therelays ZL and TL, the latter having normally closed contacts T1 to T7 inthe magnet control circuit. The top of the pile limit switch 142(FIGURES 11 and 14), which is normally closed and which is opened whenthe actuating lever 143 is engaged by the top of the pile, is in the bedelevating circuit with the pile height control switch and the maincontrol inducto switch 236. The pile height control switch 160 is openedby upward movement of the sheet lifting plungers i and closed by thedownward movement of the sheet lifting plunger 170 to cause the bedraising mechanism to operate as the sheets are removed from the top ofthe pile and to stop the upward movement of the latter at apredetermined distance beneath the lower run of the conveyor 14. Theswitch 160 is connected to the relay ZL, the latter having two contactsZLa and ZLb which are normally closed `and open, respectively, and whichare in the circuit with the main magnet contactor coil MCL. Current issupplied to the solenoid V3 (FIGURE 14) which controls the roll brakemechanism on the bed 13y from 11 the line through a spring loadedmanually operated switch 238.

In operating the Vapparatus the circuit 'breaker switches S1, S2 and S3'are closed and the selector switch 230 is set at the down position. Therelay ZB is energized and its normally open contacts ZBl and ZBZ closewhich results indownward movement of the lift bed 13 until it reachesthelower limit switch 234, the latter deenergizing the relay ZB whichopens contacts ZBl and ZB2 and stops the downV movement of the lift bedthrough operation of the solenoids VC and VB, the latter disengaging theclutch 71 and applying brake 72. The pile is then rolled onto the liftbed 13 and moves by gravity toward the discharge end of the apparatus.The horizontal positioning of the pile is controlled by the roll brakesthrough the hand switch 238. When the pile is in the proper horizontalposition the conveyor y14 is started by setting switch 231 at forwardand the selector switch 230 is manually set Aat up position. The relayZL is energized and its normally open contact ZLa is closed which closesthe circuitoperating the clutch and brake valves through solenoids VCand VB, the relay XA being energized and closing its Vnormally opencontact XAa and the lift bed 13 moves upwardly until the top of the pileengages with and raises the lift linger 170 la sufficient distance tooperate the switch 166; The switch 166 is opened by the upward movementof the actuator sleeve and relay ZL is de-energized which opens contactZLa and stops movement of lift bed A13. The coils 161 are energized tolift the fingers 170 to their uppermost lim-it and carry the leadingedge of the sheet up with them. The top sheet is lifted along its entirelength by the conveyor magnets 166 since current is supplied to energizeall the magnet coils above the top of the pile simultaneously throughthe normally closed Y v contacts T1 to T7 of the relay TL. The upwardmove- I 'C1, C2 etc. and each switch then opens to de-energize themagnetsV of the section which each switch controls,

thereby avoiding pick up of the next sheet in the pile until thetrailing edge of the sheet is clear of the pile. When the sheet movesforward of the pile the leading end of the sheet moves under the inductoswitch 236 which closes the contact 23611 and energizes the relay TLopening the normally closed contacts T1 to T7 so that when the inductoswitches C1 to C7 are openedY by .passage of the trailing end of thesheet no current is supplied to them-aguets controlled by the respectiveSwitchers. When the contact 236b closes' the normally closed contact23611 opens de-energizing relay ZL and the mechanism for elevating thebed 13 cannot operate until the sheet clears the conveyor and thetrailing edge passes the inducto switch 236. Each successive inductoswitch C1 to C7 opens as the trailing edge of the sheet passes itand themagnets controlled by it are de-energized. The coils 61 are de-energizedwhen the conveyor magnets are deenergized by theV operation of theinducto switch 236 and when the sheet advances past the lifter ngers170, the latter are freed to drop onto the next sheet in the pile whichcloses the sw-itch l160 and starts the bed 13 upwardly and the action isrepeated. When the last sheet is removed the limitV switch 2135 isactuated by the bed and operates to open the contact 235a, releasing theclutch and applying the 'brake to stop the movement of the bed i3. VTheoperator then moves the selector switch 230 to down position and the bed13 is lowered to receive a new pile. Y

VThe sheet edge lifting iingers 170 and the associated switch operatingmechanism provide a means for the operator to vary the pile level tosuit the thickness of the material beingrhandled. The i'ingers 170l alsooperate to provide an extra pull or pull and break action on the topsheet so that there is no lag in pickingV up the top sheet and thefeeding operation is constant.V The rubber ring :173 is madesuiicientlythick to protrude below the bottom of the metal core or finger member`170 so that no damage will be caused when the sheet strikes the end ofthe member and also so that the pull on the sheet will be less than thepull on the core member when the coils 161 are energized. 'This avoidsany lag in the raising of the iingers which could occur if the pull onthe core were less than the pull on the sheet. It also avoids anytendency of the fingers to lift the edge of more than `a single sheet.The coils 161 are de-energized as the bed rises and the core or lingerassembly 17), 171, 172, y173 is down. The bed 13 will rise until the topsheet lifts the finger assembly high enough to `actuate the switchthereby stopping the bed. At this time the coils 161 and the conveyormagnet coils are energized and a small pull is exerted on the edge ofthe sheet as the coils I161 raise the core or linger members 179 so thatthe edge of the sheet is raised and broken from the rest of the pile.The iingers move upwardly due to the pull of the coils 161 until theyare pulled all the way into the coils when the rubber ring 173 of eachassembly will be clear of the sheet, the pull on the fingers 170 beinggreater than the pull on the sheet by the fingers, and the sheet beingstopped by engagement with the bottom of the conveyor 14. This permitsthe sheet to be moved forward by the conveyor belts without interferencefrom the lingers 170, the latter being allowed to drop to the downposition by de-energizing the coils y161 which` occurs through operationof switch 236 as the' sheet passes out of the piler.

Preferably, inducto switches of the type described are employed inconnect-ion with the automatic control of the operating mechanism, butit will be understood that any equivalent switching mechanism which canbe actuated by movement of the sheets such as an electric eye switch,may be employed.

In the preferred for-m of the `apparatus as illustrated, verticallydisposed power driven screws 51 are employed to raise and lower the pilesupporting bed 13. However, other mechanism could be provided forvertically moving the bed .13, such as, traveling chains or hydraulicapparatus which would, of course, be connected to the bed frame in asuitable manner and provided with suitable controls for electricaloperation.

With the apparatus illustrated full power on the magnets is normallyemployed and the distance of the topmost sheet from the bottom of theconveyor magnets is preset so that the topmost sheet only is attractedby the magnets. vIf desired, the distance from the top of the pile tothe bottom of the magnets may be fixed and the voltage on the magnetsadjusted by the operator so as to accomplish the lifting ofthe topmostsheet.

While specific materials and particular details of construction havebeen referred to in describing the illustrated embodiment of theinvention, it will be understood that other materials and equivalentdetails of. construction may be resorted to within the spirit of theinvention.

I claim: Y

l. In an apparatus for handling metal sheets having an uprightsupporting structure, and an overhead magnetic conveyor, a verticallymovable pile supporting bed mounted beneath said conveyor, said bedcomprising a rectangular frame, a series of rollers mounted for freerotation in said bed frame, a brake mechanism for said rollerscomprising a brake frame mounted in vertical sliding relation on saidbed frame, support members on said brake frame which extend upwardlybetween pairs of said rollers, elongate braking plates on said supportmembers arranged below the pile engaging'p'eripheral portions of saidrollers with opposite edges adapted to be engaged with thesurfaces ofadjacent rollers upon downward movement of said brake frame relative tosaid bed frame, and power operated means to raise and lower said brakeframe.

2. In an apparatus for handling metal sheets having an uprightsupporting structure, and an overhead conveyor, a vertically movablesupporting bed mounted beneath said conveyor, said bed comprising arectangular frame, a series of rollers mounted for free rotation in saidbed frame and providing a supporting surface for a pile of sheets, abrake mechanism for said rollers comprising a brake frame mounted forvertical movement relative to said bed frame, roller engaging members onsaid brake frame which extend between pairs of said rollers, below thepile engaging peripheral portions of said rollers with opposite edgesadapted to be engaged with the surfaces of adjacent rollers upondownward movement of said brake frame relative to said bed frame, andmeans to raise and lower said brake frame.

3. In an apparatus for handling metal sheets having an upright mainsupporting structure, and an overhead sheet -lifting and advancingconveyor, a vertically movable sheet supporting structure mountedbeneath said conveyor, said sheet supporting structure comprising arectangular frame, a series of rollers mounted for free rotation in saidframe and providing a generally horizontal surface for receiving a pileof the metal sheets, a brake mechanism for said rollers comprising abrake frame, guide means for mounting said brake `frame in verticalsliding relation on said rectangular frame, elongate braking platescarried on said brake frame below the pile engaging portions of saidrollers with opposite edges thereof adapted to be engaged with thesurfaces of adjacent rollers upon predetermined movement of said brakeframe relative to said rectangular frame and power operated means toraise and lower said brake frame.

4. In an apparatus as recited in claim 3, and said power operated meanscomprising an hydraulic motor mounted on said rectangular `frame, alinkage connecting said motor to a cross shaft mounted on saidrectangular frame, and cam means on said cross shaft engaging with saidbrake frame for raising and lowering said brake frame upon rotation ofsaid cross shaft by operation of said motor.

5. ln an apparatus for handling metal sheets having an uprightsupporting structure, and an overhead sheet removing conveyor, avertically movable pile supporting bed mounted beneath said conveyor,said bed comprising a rectangular frame, a series of rollers mounted forfree rotation in said bed frame, and means vfor supporting said bedframe in tilted relation so that a pile of sheets will move by gravityacross said bed frame, a brake mechanism for said rollers comprising anelongate braking plate arranged between said rollers and below the pileengaging peripheral portions thereof with opposite edges adapted to beengaged with the surfaces of adjacent rollers upon vertical movementthereof, means to support said braking plate for vertical movement andpower operated means to raise and lower said braking plate supportingmeans.

6. Apparatus for handling metal sheets comprising a supportingstructure, a bed mounted on said supporting structure and having meansthereon for receiving a pile of metal sheets, vertical lift membersconnected to said bed, power means to operate said lift members forraising and lowering said bed, a magnetic conveyor mounted in generallyhorizontal relation above said bed, means to operate said magneticconveyor to lift successive top sheets from the pile on said bed bymagnetic force applied along the entire length of the sheet and toadvance each sheet laterally while it `is suspended above the top of thepile for delivery therefrom, and means actuated by movement ofsuccessive sheets for controlling the application of the magnetic forceto progressively cut olf the same at the trailing end of each successivesheet as it is advanced across the pile and switch means for controllingthe operation of the power means for said lift members Iwhich switchmeans is actuated in accordance `with the height of the pile of sheetson said bed whereby 14 to maintain the top of the pile on the bed at apredetermined elevation below the magnetic conveyor.

7. In an apparatus `for unpiling metal sheets, a vertically movableplatform on which a pile of sheets is supported, a magnetic conveyormounted above the platform, said conveyor having non-metallic sheetadvancing belts and cooperating magnets, the lower run of the beltsbeing spaced in a generally horizontal plane above the top of the pileof sheets so that the belts are adapted to advance each sheet laterallyof the pile while it is held against the same by magnetic force, meansfor energizing the magnets to lift each successive top sheet along itsentire length and advance the same Ilaterally across the pile withoutany metallic contact until it is clear of the pile, means toprogressively de-energize the magnets as the trailing end of each sheetpasses the same `in its advance over the pile, and means actuated byvertical movement of the top of the pile of sheets to elevate the pilesupporting platform and maintain the top of the pile of sheets at apredetermined elevation below the lower run of the conveyor belts.

8. A method of removing metal sheets from a pile thereof which comprisessupporting the pile of sheets on a vertically movable platform andcontrolling the vertical movement of the pile to maintain the topthereof at a predetermined elevation, removing successive top sheetsfrom the pile by lifting the same with magnetic force and moving eachsuccessive sheet laterally away from the pile while said sheet-issuspended by the magnetic force applied thereto and controlling theapplication of the magnetic force to the sheet to progressively cut olfthe magnetic force at the trailing end of the sheet as the sheet moveslaterally of the pile, thereby preventing the lifting of the nextsucceeding top sheet from the pile while the preceding sheet issuspended above the pile.

9. A method of unpiling metal sheets which comprises arranging a pile ofthe sheets on a movable platform, vertically moving the platform tomaintain the top of the pile of sheets at a predetermined elevation,lifting successive sheets above the top of the pile by application ofmagnetic force along the length of the sheet and advancing eachsuccessive sheet laterally of the pile while it is held suspended bymagnetic force and free of metallic contact, and progressively cuttingolf the magnetic force which is eiective at the trailing end of thesheet thereby to prevent the lifting o-f the next succeeding sheet untilthe preceding sheet is clear of the top of the pile.

10. A method of removing metal sheets from a pile thereof whichcomprises supporting the pile of sheets on a vertically movable platformand controlling the vertical movement of the pile to maintain the topthereof at a predetermined elevation, removing successive top sheetsfrom the pile by lifting the `same with magnetic force and moving eachsuccessive sheet laterally away from the pile while said sheet issuspended by the magnetic force applied thereto and controlling theapplication of the magnetic force to the sheet to progressively cut olfthe magnetic force as the sheet moves laterally of the pile therebypreventing the lifting of the next succeeding top sheet from the pilewhile the preceding sheet is suspended with portions thereof above thepile.

ll. A method of unpiling metal sheets which comprises arranging aplurality of the sheets in piled relation so that tthe topmost sheet maybe moved vertically, bodily lifting successive top sheets from the pileby applying magnetic force above the pile and 'along the entire lengthof the sheet, conveying each successive sheet laterally of the pilewhile it is suspended by magnetic force and holding the sheet clear ofany metallic contact, vertically moving the pile and maintaining the topof the pile at a predetermined elevation relative to the magnetic force,progressively cutting olf the magnetic force which is effective at thetrailing end of the sheet as each sheet is moved laterally above the topof the pile thereby to prevent the lifting of the next succeeding sheetand releasing each sheet when it is clear of the pile. t

12'. Inan apparatus for unpi'ling metal sheets, a vertically movableplatformY on which a pile of sheets is supported, a magnetic railconveyor mounted above the platform, said conveyor havinglnon-rnetallicsheet engaging traveling belts and cooperating magnets, the lower run ofthe belts being spaced in a generally horizontal plane above the top ofthe pile of sheets and arranged so that the belts advance eachsuccessive top sheet laterally of the pile when it is pulled against thebelts by the magnets, means for controlling the magnets to lift eachsuccessive top sheet along its entire length and :hold the same againstthe belts for lateral movement'without any metallic contact until it isclear of the pile, power means for moving the pile supporting platformvertically to bring the topmost sheet of the pile to a predeterminedelevation below the lower run of the conveyor belts, a solenoid unitmounted adjacent the Vleading edge of the topmost sheet in the pile andhaving a vertically movable plunger arranged to engage at the bottom endwith the top sheet of the pile, means to control the energizing of thesolenoid unit so as to exert an upward pull on the leading edge portionof the top sheet suicient to lift said edge portion of the top sheettoward the conveyor belts and means operatively connected with saidplunger for controlling the power means for the pile supporting bed soas to raise the bed in response to movement of said plunger.

13. In an apparatus for unpiling metal sheets, averlticallly movableplatformen which a pile of sheets is supporteda magnetic conveyormounted above the platform, said conveyor having a non-metallic sheetengaging A traveling belt and cooperating magnets, the lower run of thebelt-being spaced in a generally horizontal plane above the top of thepile of sheets and arranged so that I the belt will advance eachsuccessive top sheet laterally of the pile when it is pulled against thebelt by the magnets, means for controlling 'the magnets to lift eachsuccessive top sheet and thereafter to hold the same against the beltsfor 'lateral movement untilit is clear of the pile, power means formoving the pile supporting platform vertically to bring the -topmostYsheet of the pile to a predetermined elevation below the lower run Vof'the conveyor belt, one ormore solenoid units mounted above the leadingedge of the topmost sheet in the pile and each having a plunger disposedto move in a vertical path with the bottom end in position to engagewith the top sheet of the pile when the latter is raised to apredetermined position, means to control the energizingV of theVsolenoid units so as to exert an upward pull on the leading edgeportion of the top sheet suliicient to lift said edge portion of the`top sheet toward the conveyor and a switch actuated by movement ofatsolenoid plunger for controlling the power means for the pilesupporting bed so as to raise the bed a predetermined distance uponremoval of each successive sheet from the pile. j

14. In an apparatus for unpiling metal sheets, a vertically movableplatform on which a pile of sheets is supported, a magnetic railconveyor mounted above the platform, said conveyor having `anon-metallic sheet engaging travelingV belt and cooperating mag-nets,Vthe lower run of the belt being'spaced in a generally horizontal planeabove the 4top of the pile of sheets and arranged Vso that eachsuccessive top sheet will be moved laterally of the pile when it ispulled against the belt'by the magnets, means for energizing the magnetsto lift each successive top sheet along its entire length and to holdthe same against y.the belt, power means for moving the pile supportingplatform vertically to bring the topmost sheet of the pile to apredetermined position below the lower run of the conveyor, solenoidunits mounted above the lead- Aing edge portions of the topmost sheet inthe pile, each of said solenoid units having a vertically movableplunger arranged to engage at the bottom end with the top sheet of thepile when the solenoid is oie-energized andthe pile is at apredetermined elevation, means to control the energizing of the solenoidunit so that the plunger will engage with and exert an upward pull onthe leading edge portion of the top sheet suliicient Ito lift said edgeportion of the top sheet toward the bottom run of the conveyor, andmeans operative in response to movement of said plunger for controllingthe power means for moving the pile supporting bed.

15. An apparatus for unpiling metal sheets comprising a supportingframe, an overhead magnetic conveyor on the supporting frame, saidconveyor having magnets spaced along the same and traveling membersbeneath the magnets, a pile supporting platform disposed beneath theconveyor for receiving thereon a plurality of the sheets in verticallyaligned pile forming relation, means for raising and lowering theplatform, means to energize the conveyor magnets to lift successivesheets from the top of the pile and hold the same against the travelingmembers for advancing the same away from the pile, an adjustable gaugeand control mechanism responsive to the upward movement of each topsheet in the pile for operating the platform raising means so that eachsuccessive ytop sheet is positioned at a predetermined distance belowthe conveyor whereby the sheet may be picked up by the magnets in theconveyor and removed from above the pile by the traveling memberswithout disturbing the next succeeding sheet in the pile, and controlmeans for succes'sively de-energizing fthe magnets at the trailing endof the sheet as thetraveling members move the sheet across the top ofthe pile so as to avoid picking up the next sheet in the pile as it isuncovered by lateral movement of the top sheet.V

16. Apparatus for handling metal sheets comprising a supportingstructure, a rectangular bed mounted on said supporting structure andhaving rollers thereon for receiving a pile of metal sheets, verticallift members connectedrto said bed, power means to operate said liftmembers for raising and lowering said bed, a conveyor havingcontinuously traveling belts and electromagnets above the lower run ofsaid belts mounted in generally horizontal relation above said bed andcontrol means for energizing and tie-energizing the conveyor magnets soas to pick up successive sheets from the pile on said bed by magneticforce and advance said sheets across the top of the pile for deliverytherefrom,tsaid control means being actuatedby movement of successivesheets for `de-energizing the conveyor magnets Vto progressively cut otfthe magnetic force at the trailing end of each successive sheet as it isadvanced across the pile.

17. Apparatus for handling metaltsheets comprising an upright supportingframe,v a rectangular bed disposed in horizontal relation on said framefor receiving a pile of metal sheets, vertically disposed lift screwsconnected to said bed, power means to rotate said screws for raising andlowering said bed, a conveyor having longitudinally spaced magnetspositioned above the lower run of traveling sheet supporting memberswhich conveyor is mounted onrsaid supporting frame in generallyhorizontal relation above said bed, means to energize said conveyormagnets so as to pick up successive sheets from the pile on said bed bymagnetic `attraction and advance said sheets across the top of the pilefor delivery therefrom, and electrical controls for operating said powermeans and for energizing and de-energizing said conveyor magnetsincluding a first switch actuated 'by vertical movement of the top sheeton the pile whereby to control the vertical movement of said bedandmaintain automatically the height of the pile at a predeterminedelevation and a second switch actuated by forward movement of a sheet toautomatically energize the conveyor magnets for lifting successivesheets and advancing the same laterally of the pile and a series ofswitches actuated by passage of a sheet to de-energize the magnetssuccessively as the trailing end of each sheet exposes the next sheet inthe pile to the force of the magnets.

18. Apparatus as recited in claim 17 and said electrical controlsincluding a switch which is actuated upon movement of said bed to apredetermined position where the supply of sheets is exhausted and whichoperates said power means to lower the bed for receiving a new pile ofsheets.

19. In an apparatus as recited in claim 13 and each of said plungershaving a pad member of non-magnetic material on the bottom end thereofwhich is of suicient thickness to slightly space the sheet it engageswith from the bottom end of the plunger.

20. Apparatus for handling metal sheets comprising a supporting framestructure, a horizontally disposed vertically movable lift bed mountedon said supporting structure for receiving a pile of metal sheetsthereon, power operated litt members for raising and lowering said bed,a magnetic conveyor mounted on said supporting structure in generallyhorizontal relation above said bed, means to operate said magneticconveyor to lift successive top sheets from the pile on said bed bymagnetic force and to advance each sheet laterally of the pile while itis suspended above the top thereof for delivery therefrom, anon-magnetic housing extending laterally on said supporting frameimmediately beneath the delivery end of said conveyor and having avertically disposed face extending along one side of the pile supportingbed with laterally spaced, vertically extending apertures whichterminate adjacent the top of said housing, a plurality of laterallyspaced magnetic sheet edge separators mounted in said housing, each ofsaid separators comprising a vertically disposed core member havingmagnetic coils mounted thereon and upper and lower extension members onopposite ends of said core member, said separators being mounted withthe uppermost extension member terminating at the top of an aperture inthe vertical face of said housing and the lowermost extension memberterminating in vertical spaced relation to the uppermost extensionmember, means to control the operation of said lift members and said bedso as to position the edges of the top sheets in a pile on said bed inthe area between the vertically spaced core extension members of saidedge separators, and means to control the current in said separatorcoils so as to cause the leading edges of the topmost sheets in the pileto spread vertically when the conveyor is operated to lift the topmostsheet from the pile whereby the edge of the topmost sheet is raisedvertically above the top of said housing as it is lifted by saidconveyor and thereafter advanced by said conveyor across the top of saidhousing.

21. Apparatus for handling metal sheets comprising a supporting framestructure, a horizontally disposed vertically movable bed mounted onsaid supporting structure for receiving a pile of metal sheets thereon,power operated lift members for raising and lowering said bed, amagnetic conveyor mounted on said supporting structure in generallyhorizontal relation above said bed, means to operate said magneticconveyor to lift successive top sheets from the pile on said bed bymagnetic force and to advance successive sheets laterally whilesuspended above the top of the pile for delivery therefrom, anon-magnetic housing extending laterally on said supporting frameimmediately beneath the delivery end of said conveyor and having avertically disposed apertured `face extending along one side of the pilesupporting bed, a plurality of laterally spaced magnetic sheet edgeseparators mounted in said housing, each of said separators comprising avertically disposed core member having magnetic coils mounted thereonand upper and lower extension members on opposite ends of said coremember, the uppermost core extension member terminating adjacent the topof an aperture in the vertical face of said housing and adjacent the topof said housing, the lowermost extension member terminating in verticalspaced relation to the uppermost extension member, means to control theoperation of said lift members and said bed so as to position the edgesof the top sheets in a pile on said bed in the area between thevertically spaced core extension members of said edge separators, andmeans to 'control the current in said separator coils so as to cause theleading edges of the topmost sheets in the pile to spread verticallywhen the conveyor is operated to lift the topmost sheet from the pilewhereby the edge of the topmost sheet is raised vertically toward thetop of said housing as the sheet is lifted by said conveyor andthereafter advanced above said housing.

References Cited in the tile of this patent UNITED STATES PATENTS875,837 McIntyre Jan. 7, 1908 1,716,602 Ross .Tune l1, 1929 1,809,076Shinn et al. June 9, 1931 2,541,985 Chatterton Feb. 20, 1951 2,650,092Wall Aug. 25, 1953 2,650,824 Fowler Sept. l, 1953 2,766,043 BucciconeOct. 9, 1956 2,855,197 Nash Oct. 7, 1958 2,895,733 Powers July 21, 1959

